Reproduction

• Reproduction


  The joining of two gametes, the sperm and the ovum (the egg)
• Components of the male reproductive system

  • Bladder
  • Urethra
  • Penis
  • Scrotum
  • Testis
  • Sperm tube
  • Prostate gland
• Bladder


  Muscular bag to store urine
• Urethra


  Tube through the penis which carries sperm out of the penis
• Penis


  Organ that releases sperm into the vagina
• Scrotum


  Sac that holds testes at slightly lower than body temperature
• Testes


  Produce sperm
• Sperm tube


  Tube which carries sperm from testes to urethra
• Prostate gland


  Adds fluid to nourish sperm (semen)
• Sperm


  • They have a flagellum to help them swim
  • Mitochondria for energy production
  • Haploid nucleus
• Components of the female reproductive system

  • Oviduct
  • Ovary
  • Uterus wall
  • Uterus
  • Cervix
  • Vagina
• Oviduct

  Carries ova to the uterus
• Ovary


  Where the ova are produced
• Uterus wall


  Where the placenta forms after fertilisation
• Uterus


  Where the foetus develops and is nourished
• Cervix


  The opening of the uterus- it widens during birth
• Vagina

  Where the penis is placed during intercourse
• Male sex hormone


  Testosterone and it is produced in the testes
• Female sex hormone


  Oestrogen and it is produced in the ovaries
• Fertilisation

  1. The fusion of an ovum and a sperm in the oviduct

  2. Haploid nuclei of ovum and sperm fuse and form a diploid

  3. Fertilised egg is now a zygote

  4. Zygote divides by mitosis, form an embryo as it travels down oviduct to the uterus
• Placenta


  • There is a rich network of blood vessels to increase blood flow
  • There is a large number of villi to increase surface area
  • Large SA needed for exchanging dissolved nutrients
• Umbilical cord


  Contains the umbilical artery and vein to allow for exchange of gases, nutrients, waste products between the mother and foetus
• Amnion


  The membrane containing the amniotic fluid protecting the embryo
• Amniotic fluid


  Cushions the developing embryo
• Menstrual cycle


  The renewal of the blood rich lining of the uterus- this is to provide a suitable environment for a developing embryo
• The menstrual cycle lasts approximately 28 days
• Stages of the menstrual cycle

  • Menstruation (1-5)
  • Following menstruation (6-13)
  • Ovulation (13-15)
• Menstruation

  The breakdown and removal of the uterus lining at the end of each cycle. Lasts from puberty to 44-55 years
• Days after menstruation


  The rebuilding of the uterus lining to prep for fertilisation
• Ovulation


  The release of an ovum from the ovary
• Oestrogen in the menstrual cycle


  Causes the repair and build up of uterus lining and stimulates ovulation
• Progesterone in the menstrual cycle

  Maintains the build up of uterus lining and prepares uterus for pregnancy
• Fertilisation is most likely to occur during days 13-15
• Fertility drugs


  Increase egg production and release
• In vitro fertilisation


  1. Stimulation

  2. Egg retrieval

  3. Insemination

  4. Pregnancy
• Sperm cells

  Specialised cells formed by meiosis
• Fertilisation takes place in the oviducts when the haploid sperm and egg nuclei fuse to give a diploid zygote
• Causes of infertility


  • Blocked Oviducts
  • Eggs are not released
  • Low Sperm Count
  • Impedience
• Male condoms


  Barrier to prevent sperm entrance
• Pros and cons of male condoms

  • Easily obtained
  • Protects against STIs
  • Unreliable if not used properly